Borussia Dortmund have stoked up the fires ahead of tonight’s Champions League clash with a fierce attack on City’s wealth.

The German club’s chief executive Hans-Joachim Watzke even suggested he would have slammed the door on City owner Sheikh Mansour had he tried to make massive investment in his club.

Watzke also suggested that clubs like the Blues should be thrown out of the Champions League if they try to bend the new financial fair play rules.

“UEFA must find the thin line between sponsorship and excessive back-door funding – they must show strength to expel big clubs,” said Watzke, whose club is 51 per cent owned by its supporters and has a strict policy not to allow spending to exceed their income.

Watzke said Mansour would not have been allowed to take over Dortmund, citing the problems at Malaga, who have hit financial problems after Qatar’s Sheikh Abdullah Al Thani appeared to lose interest after taking over the club.

“I would not even welcome him,” said Watzke when asked what his reaction would be if a rich foreign investor showed interest in Dortmund. “What if the sheikh, as shown by Malaga, lost interest?

“The fact is that the Bundesliga has caught up considerably, thanks to their sound banking practices. This will eventually be expressed by results.”